23 weeks pregnant husband wants to seperate

My husband and I have been married for 2 years and together for 8. We have had an Amazon gift relationship or so I thought. Everyone was always saying you two are so amazing together. We went on vacations and loved being each other's best friends! My husband suffers from anxiety and depression and was recently diagnosed with High Functioning Autisim. We planned this pregnancy and everything was wonderful until a few weeks ago. He became very distant and when I asked him what was going on he said he wasn't happy and needed space to figure out who he is and the person he is becoming. He said he hasn't been happy since before we got married and thought that the marriage and baby would make things better but it just hasn't. This can't be true anyone we have been around and all the things we have done he has clearly enjoyed our cruises and vacations, yes he has periods of "down" depression but never lasted long. This all comes as a shock to me because I always knew he was going through his own problems but thought that I and our relationship ship was the one thing that brought happiness to him. So when he said he didn't think he wanted to be married and needed space I packed somethings and went to my parents 3 hours away. I did the things I probably shouldn't have in the beginning messaging him constantly and begging him to try to fix this and love me again. He only pushed farther away. I now haven't spoken to him in several days and we agreed to not get a divorce at this time just take some space for a while to be sure before filing for divorce. I love this man with all my heart and feel like we can be the family we always talked about being but I am afraid I have really lost him. Has anyone else's gone through this? Will he come around by the time the baby is here?